1. Field of the Invention
This invention concerns pulse-echo type wall thickness measuring in general. More specifically, it relates to a method and system for improving upon known pulse-echo types of wall thickness measurement.
2. Description of the Prior Art
In the field of non destructived testing, or measuring of thickness of the walls of elongated bodies, use has been made of a longitudinally directed pulse transducer with a 45 degree reflecting surface so as to direct the energy from a parallel direction to one at right angles that is thus transverse to the walls of the elongated body. Also, in connection with pipe line inspection employing pulse-echo systems, it has been known to make use of a plural transducer with rotator, which employed a scanning or a physical rotation at a rate proportional to the longitudinal travel in the pipe. However, neither of the prior arrangements conceived of simultaneously introducing another pulse directed at a different angle relative to the surface of the pipe or other wall. This invention makes use of the latter method in conjunction with known elements and arrangements, to provide for an improved method and system for determining a characterization of a discontinuity so as to be able to recognize a cavity or thin spot, as distinguished from a welded joint or the like.
Thus, it is a object of this invention to provide an improved method or system for measuring wall thickness with a pulse-echo type of system while employing an additional means for characterizing a discontinuity in said wall thickness that may be observed.